Dental-engine stone and mandrel.



J. W. WELCH.

DENTAL ENGINE STONE AND MANDRBL.

APPLICATION FILEDZOGT. 7, 1912.

Patented Nov. 4, 1913.

Viz/2446 244 Q C? M111 COLUMBIA PLANOGRAPH c UNITED STATES PATENT QFIQE.

JOHN W. WELGH, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-FOURTH '10 EDWARD L. CHOTT AND ONE-FOURTH TO HUG-O J. CHOTT, OF CHICAGO, ILLINOIS.

DENTAL-ENGINE STONE AND MANDREL.

T aZZ whom 2'2 may concern Be it known that I, JOHN WV. TELOH, a

I citizen of the United States, and aresident of the city of Chicago, county of Cook, and State of Illinois, have invented certain new and useful Improvements in Dental-Engine Stones and Mandrels, of which the following is a specification.

My invention relates to improvements in dental-engine stones and mandrels and has for its object the production of a dentalengine stone and mandrel which will be so connected as to absolutely prevent relative rotary movement of said stone and mandrel so as to permit of rotation of the stone or abrasive element in either direction without fear of the latter becoming loosened.

A further object is the production of a stone and mandrel of the character mentioned which will be so connected as to permit of ready and expeditious detachment of the stone when desired in order to permit of replacement of the stone or for any other reason.

A still further object is the production of a tool of the character mentioned which will be of simple and economical construction and efficient in use.

Other objects will appear hereinafter.

The invention consists in the combinations and arrangements of parts hereinafter described and claimed.

The invention will be best understood by reference to the accompanying drawing forming a part of this specification, and in which,

Figure 1 is a sectional side elevation of a dental-engine stone and mandrel embodying my invention. Figs. 2 and 8 are perspective views of the mandrel and stone dis connected, and Figs. 4 and 5 and 6 and 7 are views similar to Figs. 2 and 8, respectively, showing slightly modified forms of the construction.

The preferred form of construction as illustrated in the drawings comprises a cylindrical mandrel 1 provided at one end with a circumferential fiange or shoulder 2. Arranged at said end of said mandrel is the stone or abrasive element 3 which is detachably secured to said mandrel by means "of a headed screw 4 which passes centrally through the stone 3 and which is threaded in a threaded socket 5 formed centrally in the adjacent end of said mandrel The Specification of Letters Patent.

Application filed October 7, 1912.

Serial No. 724,352.

flange 2 engages, as shown, a recess 6 which is formed in the adjacent side of the stone 3, sa1d recess passing only partly through said stone, so that the stone will be clamped in position between the outer end of the mandrel and the head of the screw 4. Said flange 2 is of polygonal or rectilinear form in cross-section and the recess 6 is of corresponding form so that the stone and mandrel will be absolutely locked against relatlve rotary movement. Said flange and recess may be of any one of a variety of different forms it being only essential that the same are not circular since with the latter construction the absolute locking of the stone and mandrel against relative rotary movement would not be secured.

With a dentalengine stone and mandrel of the construction set forth it will be seen that the stone is securely fastened to the mandrel against relative movement in all directions, but in such a manner that the same may be readily and expeditiously de- Patented Nov. 4, 1913.

tached when desired in case the stone becomes worn or disabled or in order to permit of another stone being secured in its place, this being effected by simply removing the securing screw 4. With this arrangement a dentist needs only to be equipped with one mandrel since the same will be adapted for use in conjunction with any stone which is recessed to correspond therewith. A great saving will be thus secured as will be appreciated by those skilled in the art. The outer end of the socket 5 is counter-sunk in order to facilitate insertion of the point of the screw in the attachment of a stone to the mandrel.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. I, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such varia tions and modifications as come within the scope of the appended claims.

Having described my invention what I claim as new and desire to secure by Letters Patent is:

1. The combination of a mandrel; an abrasive element arranged at one end of said mandrel, said mandrel end fitting snugly a recess formed in one side of said element extending partly through the latter; and means for locking said abrasive element to said mandrel, said recess and engaging end of said mandrel being of corresponding non-circular form, substantially as described.

2. The combination of a mandrel; an abrasive element arranged at one end of said mandrel said mandrel end fitting snugly a recess formed in one side of said element means in threaded connection with said mandrel for locking said abrasive element to said mandrel said recess and engaging end of said mandrel being of corresponding non-circular form, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

JOHN W. WELGH. WVitnesses A. A. OLSON, JOSHUA R. H. Po'rrs.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, D. G. 

